Greenwald talks about Walmart being a value trap, and states that American Express is a good buy. Greenwald is known for being bearish on Walmart. He thinks they do not have an edge in places overseas where they are trying to expand. He believes the company would be better off expanding into untapped domestic markets where the company has an edge. That is how Walmart began its dominance by slowly expanding from outside of Arkansas. Walmart will have no edge by opening up a store in Shanghai or some other distant city.